Regulator having removable first stage orifice body

ABSTRACT

A first stage pressure regulator is provided. A valve body has an inlet and an outlet that define a pressure chamber therebetween. The valve body defines a pressure compensation chamber having an opening fluidly communicating the pressure compensation chamber with the surrounding water. The first stage pressure regulator comprises an inlet tubular union removably received into the inlet. A removable high pressure orifice body defines an orifice therethrough. The orifice body is carried by the valve body proximate the inlet. A valve seat is within the valve body.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a Divisional of co-pending U.S. patentapplication Ser. No. 14/454,444, filed Aug. 7, 2014, the entireteachings and disclosure of which are incorporated herein by referencethereto.

FIELD OF THE INVENTION

This invention generally relates to a first stage regulatory valve foruse in a self-contained underwater breathing apparatus.

BACKGROUND OF THE INVENTION

First stage pressure regulators for underwater breathing convert highpressure gas to a lower pressure at or near a pressure that can bebreathed by a diver. The high pressure gas is generally supplied to thefirst stage pressure regulator from an outlet of a cylinder ofcompressed air at a pressure that may be in excess of 4,000 psi.

The high pressure gas is received by the first stage pressure regulatorthrough an orifice of the first stage pressure regulator into a highpressure chamber of the valve body of the first stage pressureregulator. Orifice sizes, hardness, and sealing surfaces contribute tothe efficiency and amount of high pressure air passing into the highpressure chamber of the valve body. Heretofore, the high pressure gashas been received into the high pressure chamber of the valve bodythrough an orifice formed into and of the valve body.

Such high pressure receiving orifices that are integral with the valvebody have resulted in complex and time consuming machining of the firststage pressure regulating valve body. Additionally, because the orificeis integral with the valve body the hardness of the outer sealing edgesof the orifice is limited to the same material and hence the samehardness of the valve body itself. Accordingly, the sealing edge of theorifice has proven difficult to protect from wear. Further, it has beendifficult to protect such an integral orifice from corrosion because itslocation within the valve body makes it difficult to coat withanti-corrosion materials. Still further, quality control of the integralvalve body orifice must be done with the valve body itself as opposed tobeing able to do quality control of the orifice independent of the valvebody. Moreover, maintenance of such orifices has proven difficult sinceits wear is wear of the valve body itself.

The present invention seeks to provide improvements over the currentstate of the art of first stage pressure regulators for underwaterbreathing devices. These and other advantages of the invention, as wellas additional inventive features, will be apparent from the descriptionof the invention provided herein.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the invention provides a first stage pressure regulatorcomprising a valve body having an inlet and an outlet that define apressure chamber between the inlet and an outlet. The valve body definesa pressure compensation chamber having an opening fluidly communicatingthe pressure compensation chamber with the surrounding water. The firststage pressure regulator comprises an inlet tubular union removablyreceived into the inlet. A removable high pressure orifice body definesan orifice therethrough. The orifice body is carried by the valve bodyproximate the inlet. A valve seat is within the valve body.

A valve member is slidably carried within the valve body pressurechamber. The valve member has a valve end. The valve seat is carried bythe valve end. The valve member is slidable between an open state and aclosed state. In the open state the valve end carrying the valve seat isspaced from the removable high pressure orifice permitting fluid flowthrough the orifice between the inlet and outlet. In the closed statethe valve end carrying the valve seat is sealingly seated against theremovable high pressure orifice body preventing fluid flow between theinlet and outlet.

In an embodiment, the removable high pressure orifice body may includean upstream end in the form of a T-shaped head having a larger diameterthan a downstream end. The orifice body may extend downstream of theT-shaped head into the inlet.

In another embodiment, a bottom surface of the T-shaped head is seatedupon an outward facing surface of the inlet of the valve body. A topsurface of the T-shaped head is in contact with the inlet tubular unionsuch that the tubular union secures the orifice body in the inlet.

In an embodiment, the T-shaped head may fit inside a cavity at a distalend of the inlet tubular union. The T-shaped head may include a slotthat fluidly communicates a high pressure passage surrounding theT-shaped head with a center passage of the inlet tubular union. The highpressure passage is in fluid communication with a high pressure exitport of the valve body.

In an embodiment, a head of the removable high pressure orifice body isinside a cavity formed in a distal end of the inlet tubular union.

In another embodiment, a T-shaped head of the high pressure orifice bodyis dimensioned to fit within a cavity of the inlet tubular union.

In yet another embodiment, the orifice body is axially movable and theinlet tubular union limits axial motion of the orifice body.

In another embodiment, an end of the removable high pressure orificebody is in sealing contact with the valve seat in the closed state.

In yet another embodiment, the valve body comprises a material of afirst hardness and the removable high pressure orifice is comprised of amaterial of a second hardness greater than the first hardness.

In still another embodiment, the removable high pressure orifice bodygenerally includes a T-shaped head at an upstream end; a conicalprotrusion at a downstream end; a slot formed into a top surface of theT-shaped head; an annular groove formed into the valve body proximate anaxial center of the orifice body. The annular groove receives an O-ring;the O-ring is in sealing contact with walls of the inlet of the valvebody. The conical protrusion terminates at a tip; the tip is in sealingcontact with the valve seat in the closed state.

In another embodiment the removable high pressure orifice is free offastening threads.

In yet another embodiment the compensation chamber includes an insulatedbushing; an insulating ring an insulating sleeve and an insulatingbiasing member.

In another aspect, the invention provides a method of assembly of afirst stage pressure regulator. The method includes seating a removablehigh pressure orifice that defines an orifice in an inlet of a valvebody. The method includes securing an inlet tubular union to the valvebody to limit axial motion of the orifice body within the inlet betweenthe inlet tubular union and the valve body.

In an embodiment, the valve body has an inlet and an outlet and thatdefine a pressure chamber between the inlet and an outlet. The valvebody defines a pressure compensation chamber having an opening fluidlycommunicating the pressure compensation chamber with the surroundingwater.

The valve body includes a valve seat within the valve body. A valvemember is slidably carried within the valve body pressure chamber andhas a valve end and an expansion head connected to the valve end. Thevalve member is slidable between an open state and a closed state. Inthe open state the valve end carrying the valve seat is spaced from adownstream end of the removable high pressure orifice permitting fluidflow between the inlet and outlet. In a closed state the valve endcarrying the valve seat is sealingly seated against the downstream endof the removable high pressure orifice preventing fluid flow between theinlet and outlet. The expansion head is exposed to the pressurecompensation chamber and is operably acted upon by the surrounding waterwithin the pressure compensation chamber to bias the valve member towardthe open state. A biasing member is carried within the compensationchamber to bias the valve member towards the open state.

The removable high pressure orifice body of the method may include aT-shaped head at an upstream end, a conical protrusion at a downstreamend, a slot formed into a top surface of the T-shaped head, a centralpassage through the valve body and an annular groove formed into thevalve body at approximate a longitudinal center of the orifice body.

In an embodiment, the step of securing is threading.

In another embodiment, the step of securing includes receiving a head ofthe removable high pressure orifice body in a cavity in a distal end ofthe inlet tubular union.

In yet another aspect, the invention provides a method of servicing afirst stage pressure regulator. The method comprises removing aremovable high pressure orifice body from an inlet of a valve body. Themethod includes modifying the removable high pressure orifice body andincludes the step of reinserting the repaired orifice body into and onthe inlet of the valve body.

In an embodiment, the step of modifying the removable high pressureorifice body may include machining a new diameter of a flow restrictionorifice of the removable high pressure orifice body that is of greaterdiameter than an original diameter of the flow restriction orifice.

In yet another embodiment, the step of securing fixes the orifice bodywithin the inlet between the inlet tubular union and the valve body.

In yet another embodiment, the step of modifying may include replacingthe removable high pressure orifice body with a second removable highpressure orifice body.

Other aspects, objectives and advantages of the invention will becomemore apparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention and,together with the description, serve to explain the principles of theinvention. In the drawings:

FIG. 1 illustrates an axial section of an embodiment of the pressureregulator valve according to the present invention with the valve memberin a closed position.

FIG. 2 illustrates an enlarged view of a downstream portion of an inlettubular union of the pressure regulator of FIG. 1.

FIG. 3 illustrates an elevated perspective view of a removable highpressure orifice body of the pressure regulator of FIG. 1.

While the invention will be described in connection with certainpreferred embodiments, there is no intent to limit it to thoseembodiments. On the contrary, the intent is to cover all alternatives,modifications and equivalents as included within the spirit and scope ofthe invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a first stage air pressure reduction valve 10 of atwo stage system. The first stage air pressure reduction valve 10 mayalso be referred to as first stage pressure regulator 10 or even moresimply as pressure regulator 10. The first stage pressure regulator 10is used to reduce the pressure of high pressure gas stored, typically,in a tank carried by a diver to a more manageable pressure that is usedby a second stage regulator that supplies breathing gas to the diver.Typically, the high pressure gas source approximates 4000 psi. The highpressure air is compressed air that may be a mixture of oxygen and othersuitable gases for diving. For simplicity, hereinafter, the air or gasmixture will be referred to as gas.

The pressure regulator 10 generally includes a valve body 12. In theillustrated embodiment, the valve body 12 is generally a two piece valvebody having two components 13 and 15 attached to one another. In thisembodiment, the components 13 and 15 are threadedly connected to oneanother. The valve body 12 may be constructed of brass and coated in ananti-corrosion material such as chrome.

The valve body 12 is joined to a supply of compressed air (not shown),such as a cylinder of compressed air, by an inlet tubular union 14attached to a high pressure inlet 16 of the valve body 12. As with thevalve body 12, the inlet tubular union 14 may be made of brass andcoated in an anti-corrosion material such as chrome. In this embodiment,the inlet tubular union 14 is threadedly connected to the high pressureinlet 16 of the valve body 12. The inlet tubular union 14 is a conduithaving a center passage 18 surrounding a center axis 20 of the inlettubular union 14. High pressure air flows from the cylinder through thecenter passage 18 and selectively into and through an orifice 22 of aremovable high pressure orifice body 23. With additional reference toFIG. 2, the center passage 18 of the inlet tubular union 14 has acentral portion of a first diameter 26 and a downstream portion 32 thatincludes an annular cavity 44 having a second diameter 34 that isgreater than first diameter 26 formed by a stepped portion of the innersurface of inlet tubular union 14. The center passage 18 may be coaxialand concentric with a center axis 36 of the orifice 22 of the removablehigh pressure orifice body 23.

FIG. 2 illustrates an enlarged view of the downstream portion 32 of theinlet tubular union 14. The downstream portion 32 has an outermostsurface 40 that forms a distal end of the tubular union 14 that maycontact or simply come very near without contacting an axially outwardfacing surface 42 of the high pressure inlet 16 of the valve body 12.The annular cavity 44 is formed into the outermost surface 40 of thedownstream portion 32 of the inlet tubular union 14. The annular cavity44 is in the form of a cylindrical cavity having diameter 34 and havinga smooth planer surface 46 and a sidewall 47 extending axially betweensurfaces 40 and 46. The depth 48 of the annular cavity 44 is defined asthe distance from the surface 40 of the downstream portion 32 of theinlet tubular union 14 to the upstream surface 46 of the cavity 44 andcorresponds to sidewall 47. In an embodiment, the depth 48 of the cavity44 may be configured to seat orifice body 23 against component 13 of thevalve body 12 and thereby fix the orifice body 23 between the inlettubular union 14 and the valve body 12. In another embodiment, thecavity 44 is spaced upstream of surface 42 far enough to permits theorifice body 23 to move axially within the cavity 44 with surface 40 and46 acting as stops to limit the axial movement of the orifice body 23.

Thus, the depth 48 of the cavity 44 of the inlet tubular union is suchthat a T-shaped head 52 of the removable high pressure orifice body 23is received into the cavity 44 and is sandwiched between the planarsurface 46 of the cavity 44 of the inlet tubular union 14 and the valvebody 12. More specifically, a top surface 55 (FIG. 3) of the T-shapedhead 52 may be in contact with the bottom surface 46 of the inlettubular union 14 while the orifice body 23 is in axial contact with andthus seated upon valve body 12. A slot 53 (FIG. 3) is formed into thetop surface 55 of the T-shaped head 52.

The slot 53 provides a means by which high pressure air in the centerpassage 18 of the inlet tubular union 14 fluidly communicates with ahigh pressure passage 116 when the planar surface 46 of the inlettubular union is in contact with the top surface 55 of the T-shaped head52. The fluid communication is possible because the diameter 120 of theT-shaped head is less than the diameter 34 of the cavity 44 and thus anannular high pressure passage 116 is formed that surrounds the T-shapedhead and fluidly communicates with a high pressure exit port 118 of thevalve body 12. The high pressure exit port 118 may permit a highpressure gauge to attach to the valve body 12 via the exit port 118 toenable a diver to read the pressure of the tank (not shown) containingthe high pressure air.

In another embodiment, as shown in FIG. 2 planar surface 46 of thecavity is not in contact with the top surface 55 of the T-shaped headand thus the orifice body 23 is free to move in an axial direction andis thus held in place against the valve body by the high pressure air incontact with the top surface 55 of the T-shaped head. It can be readilyappreciated that the axial movement of the orifice body 23 is notwithout limits, that is, the planar surface 46 acts as a stop forlimiting the axial movement of the orifice body 23. In this embodimentit is the high pressure gas acting against the orifice body 23 thatseats the orifice body 23 against the valve body 12. In this embodimenta gap 122 is created between planar surface 46 and top surface 55. Thegap 122 is in fluid communication with the annular high pressure passage116 which in turn, as previously discussed is in fluid communicationwith the high pressure exit port 118 of the valve body 12.

The inlet tubular union 14 may be threadily received into the highpressure inlet 16 of the valve body 12 and over the top surface 55 ofthe T-shaped head 52. Although, threading is shown, it is not the intentto limit reception by threading as other fastening means may be used.Thus, it can be readily appreciated that insertion of the removable highpressure orifice body 23 takes place prior to threading the inlettubular union 14 into the high pressure inlet 16 of the valve body 12.The fastening of the inlet tubular union 14 to the high pressure inlet16 of the valve body 12 easily secures the removable high pressureorifice body 23 between the inlet tubular union 16 and the valve body 12during assembly. More specifically, the T-shaped head 52 of the highpressure orifice body 23 is received into the cavity 44 of the inlettubular union 14 as the inlet tubular union 14 is threaded, as shown inthis embodiment, into the high pressure inlet 16 of the valve body 12.Further, during disassembly of the regulator 10 one need only tounthread the inlet tubular union 14 from the high pressure inlet 16 ofthe valve body 12 in order to access the removable high pressure orifice22. Once the inlet tubular union 14 is removed from the inlet 16, theremovable high pressure orifice body 23 can be easily removed from theinlet 16. The removal may be done, for example, by a simple grasp andlight pull of the T-shaped head 52 and/or simply allowing gravity to letthe removable high pressure orifice body 23 to fall from the inlet 16.

The removable high pressure orifice body 23 provides for less complexmachining processes with respect to forming the valve body 12 (or theinlet tubular union 14). Heretofore, a high pressure orifice wasmachined as part of the valve body 12 (or inlet tubular union 14). Suchmachining can be readily understood to be more complex and timeconsuming than a valve body 12 (or inlet tubular union 14) that does nothave an integral high pressure orifice.

Because the orifice 22 is no long machined into the valve body 12 anembodiment of the removable high pressure orifice 22 may provide for aremovable high pressure orifice body 23 made of a material of a firsthardness while the valve body 12 may be made of material of a secondhardness. In a preferred embodiment, the first hardness may be greaterthan the second hardness. For a non-limiting example, the high pressureorifice 22 may be made of stainless steel while the valve body 12 may bemade of nickel-brass. Because the removable high pressure orifice body23 may be of a greater hardness than the valve body 12, sealing edges 28of the removable high pressure orifice body 23 will wear more slowlythan mating surfaces of the valve body 12.

The removable high pressure orifice body 23 defines orifice 22 thatreceives high pressure air from the center passage 18 of the inlettubular union 14. The central orifice 22 of the removable high pressureorifice body 23 has a diameter 74 that is less than the diameter 26 ofthe center passage 18 of the inlet tubular 14 and thus acts as a flowrestriction. In an embodiment the diameter 74 of the orifice 22 of theremovable high pressure orifice body 23 may be between 1 and 4 mm. In apreferred embodiment the diameter of the orifice may be between 1.5 mmand 3 mm and in a more preferred embodiment the diameter 74 may bebetween 1.9 mm and 2.1 mm.

The replaceable high pressure orifice body 23 as heretofore describedhas shown the unexpected result of as much as 15% increased airflowthrough the pressure regulator valve 10 as compared to similar pressureregulator valves having a high pressure orifice integral with the valvebody 12.

Further, by providing a removable high pressure orifice body 23 thevalve body 12 and the inlet tubular union 14 can more easily beprotected from corrosion. In a preferred embodiment, the high pressureinlet 16 of the valve body 12 and the inner surface of the inlet tubularunion 14 are smooth as opposed to inner surfaces having threads or otherinternal grooves. This presents an advantage because smooth continuoussurfaces are more easily protected from corrosion with anti-corrosioncoatings than are those with threads or grooves that are difficult tocoat.

Still further, with such a readily removable high pressure orifice body23 quality control of the removable high pressure orifice 22 may be doneindependently of the valve body itself 12 and thus results in moreprecise and timely quality control as opposed to an orifice integralwith the valve body 12. Such a removable high pressure orifice body 23saves repair costs where, for example, the entire valve body 12 (orinlet tubular union 14) has to be re-machined upon a machining error orupon wear of a high pressure orifice integral thereto. The ease ofremoving the replaceable high pressure orifice body 23 allows for simplyreplacing the high pressure orifice body 23 when worn or re-machiningthe high pressure orifice body 23 or simply replacing an annular radialseal 54 of the high pressure orifice body 23.

Turning now to FIG. 3, the removable high pressure orifice body 23 aswas discussed above, has a T-shaped head 52 having a slot 53 at anupstream end 56. The T-shaped head 52 provides the means by which theremovable high pressure orifice body 23 mates with the valve body 12 andis received into the cavity 44 of the inlet tubular union 14. (See FIGS.1 and 2) At a downstream end 58 of the removable high pressure orificebody 23 there is an annular planar flange 60 and a conical protrusion 64that mates with and is received by corresponding surfaces 67 of valveseat 66 (FIG. 1). An annular groove 68 is provided in approximately theaxial center of removable high pressure orifice body 23. Axial is to beunderstood in this context as between the upstream end 56 of theremovable high pressure orifice body 23 and the downstream end 58 of theremovable high pressure orifice body 23 and corresponds to central axis36. The annular groove 68 provides sealing and bearing surfaces 70 forthe annular radial seal 54 carried therein. The annular radial seal 54also bears against and seals with an annular interior wall 72 (FIG. 2)of the high pressure inlet 16 of the valve body 12 so as to prevent anygas or liquid from bypassing orifice 22.

Turning again to FIG. 1, the valve body 12 provides a pressure chamber76 and a compensation chamber 78. The pressure chamber 76 andcompensation chamber 78 may be concentric and coaxial. The pressurechamber 76 and compensation chamber 78 are separated from one another bya partition wall 80 and a valve member 82 that is movable.

The pressure chamber 76 communicates via the inlet tubular union 14 andorifice 22 of the removable high pressure orifice body 23 with thepressurized gas supplied into the pressure regulator 10 from thecylinder of compressed gas. The compensation chamber 78 communicateswith the outside ambient water through openings 84 in the valve body 12.During a dive, the compensation chamber 78 fills with water at apressure corresponding to the dive depth.

The valve member 82 is slidingly carried within the valve body 12. Thevalve member 82 has an expansion head 86 that is connected to a valveend 88 by a tubular stem 90. The tubular stem 90 and expansion head 86are both sealed to the valve body 12 to prevent ingress of ambient wateror egress of the gas within the regulator. The tubular stem 90 andexpansion head 86 are also allowed to slide axially within the valvebody 12 as illustrated by arrow 92 so as to allow the pressure regulator10 to reduce the pressure of the gas from its inlet pressure.

The tubular stem 90 is preferably a metal material such as stainlesssteel to ensure a better resistance both mechanically and chemically(saline, etc.). In this embodiment, the tubular stem 90 defines thevalve end 88.

The valve end 88 is shaped to carry valve seat 66. The valve end 88carrying valve seat 66 selectively seats against the distal end of thetapered protrusion 64 of the removable high pressure orifice body 23.When the valve end 88 is spaced away from valve seat 66, the pressureregulator 10 is in an open state and gas is allowed to flow through theorifice 22 to outlet 94 of the valve body 12 and into the tubular stem90 through passage 83. This configuration is illustrated in FIG. 1. Whenthe valve end 88 is biased against the distal end of the taperedprotrusion 64, the fluid flow path from the inlet tubular union 14through the orifice 23 of the removable high pressure orifice body 23 isclosed preventing fluid flow.

The valve seat 66 is preferably of a non-metallic material so as toprovide a good sealing engagement with the valve end 88 and the distalend of the tapered protrusion 64 of the removable high pressure orificebody 23 when the valve member 22 is in a closed state.

The expansion head 86 is at an end opposite valve end 88 of the valvemember 82 and has an enlarged conical shape. Gas passes from thepressure chamber 76 into passage 83, through the tubular stem 90 andinto the enlarged area provided by the conical shape of the expansionhead 86. This conical shape provides an enlarged area in which the gasis allowed to expand. The exterior surfaces of the expansion head areacted on by the water within the compensation chamber 78 to bias thevalve member 82 toward the open state (e.g. in the direction of arrow96). The interior surfaces of the expansion head 86 are acted on by thegas sealed within the pressure regulator 10 to bias the valve member 82towards the closed state (e.g. in the direction of arrow 98).

A coil spring 100 is located within the compensation chamber 78 to biasthe valve member 82 toward the open state (e.g. in the direction ofarrow 96) with a minimum predetermined amount of force. The coil spring100 is interposed between the expansion head 86 and the valve body 12,and particularly a portion of the partition wall 80. The coils of thespring 100, in this embodiment, are formed by a stainless steel core 102covered by a thermal insulating material layer 104.

As gas flows from orifice 22 to the outlet 94 and through the valvemember 82, the gas is allowed to expand and drop in pressure. Thisexpansion and pressure drop is an endothermic process that draws heatenergy out of the components of the pressure regulator 10 that surroundthe pressure chamber 76, such as the valve body 12 and the valve member82.

Because of the endothermic gas expansion, the compensation chamber 78 issubjected to a temperature drop which can cause freezing of the waterwithin the compensation chamber 78. Ice formation within thecompensation chamber 78 can affect the operation of coil spring 100,valve member 82 or the openings 84 and inhibit the pressure compensationfeature of the pressure regulator 10.

One particular location where freezing occurs is proximate the end ofthe coil spring 100 that is pressed against the valve body 12. Toaddress the freezing problems within the compensation chamber 78, theillustrated embodiment includes a thermally insulated bushing 106 thatcovers the outer surfaces of the valve body 12 proximate the locationwhere the coil spring 100 is supported.

The thermally insulated bushing 106 is preferably made of thermalinsulating plastic material, which can also include a suitable fillingmaterial, such as for instance empty microspheres embedded in theplastic to improve the thermal insulation and inhibit heat transfer fromthe water within the compensation chamber to the valve body 12 andpressure regulator 10, generally.

Additional insulation may be provided by thermally insulating with aninsulating sleeve 112 the expansion head 86 surfaces acted upon by thewater. Still more insulation may be provided by insulating the externalsurfaces exposed to water of the valve stem 90 with both the sleeve 112and an insulating ring 114 that surrounds a portion of tubular stem 90.The insulating sleeve 112 and insulating ring 114 in a non-limitingembodiment are of the same material as that discussed above with respectto insulated bushing 106. An annular part 108 of the expansion head 86carries on its outer radial periphery a watertight ring (O-ring) 110.

The surfaces exposed to the ambient water (also referred to as the “wetarea”) of compensation chamber 78 are substantially insulated, e.g.formed from an insulating material. In some embodiments, more than 80%of the surfaces in compensation chamber 78 are insulated and in yetother embodiments at least 90% of the surfaces in compensation chamber18 are insulated. Because of the thermally insulated means heretoforediscussed, heat transfer from the water within the compensation chamber78 is reduced which inhibits freezing of the water within the pressurecompensation chamber 78 during cold water dives, at least for the lengthof time of a normal diving, thus avoiding the inefficiency or theeventual valve blocking and the associated risks for the user.

The invention provides a method of servicing the first stage pressureregulator 10. The method includes removing a removable high pressureorifice body 23 from an inlet 16 of the valve body 12. The removal maybe, as a non-limiting example unthreading the inlet tubular union 14from the valve body 12 and allowing gravity to let the removable highpressure orifice body 23 to drop from valve body 12. The removable highpressure orifice may then be modified by machining or simply replacingthe entire removable high pressure orifice body 23 with a new orificebody.

As can be readily appreciated, the orifice diameter 74 of the originalorifice body 23 that has worn may be machined to a greater diameter orsimply cleaned so as to retain the original orifice diameter 74. Thesealing surfaces of the orifice body may be machined or cleaned as welland as previously discussed the annular seal 54 may be replaced.

On the other hand, as discussed, modifying may mean the orifice body 23is replaced with a second orifice body, that is, a new orifice body. Inthat case, the orifice diameter may equal the diameter 74 of theoriginal orifice 22 or the orifice diameter may have a smaller diameteror greater diameter and thereby provide for an orifice diameter of aflow restriction different than the original orifice 22.

All references, including publications, patent applications, and patentscited herein are hereby incorporated by reference to the same extent asif each reference were individually and specifically indicated to beincorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

What is claimed is:
 1. A method of assembling a first stage pressureregulator, the method comprising: seating a removable high pressureorifice body defining an orifice in an inlet of a valve body; securingan inlet tubular union into the inlet of the valve body; whereinsecuring the inlet tubular union to the valve body limits axial motionof the orifice body within the inlet between the inlet tubular union andthe valve body.
 2. The method of claim 1, wherein the valve body has aninlet and an outlet and defining a pressure chamber between the inletand an outlet, the valve body defining a pressure compensation chamberhaving an opening fluidly communicating the pressure compensationchamber with the surrounding water; a valve seat within the valve body;a valve member slidably carried within the valve body pressure chamberhaving a valve end and an expansion head connected to the valve end, thevalve member slidable between an open state in which the valve endcarrying the valve seat is spaced from a downstream end of the removablehigh pressure orifice permitting fluid flow between the inlet and outletand a closed state in which the valve end carrying the valve seat issealingly seated against the downstream end of the removable highpressure orifice and that prevents fluid flow between the inlet andoutlet, the expansion head being exposed to the pressure compensationchamber and being operably acted upon by the surrounding water withinthe pressure compensation chamber to bias the valve member toward theopen state; a biasing member carried within the compensation chamber tobias the valve member towards the open state.
 3. The method of claim 2,wherein the removable high pressure orifice body has: a T-shaped head atan upstream end; a conical protrusion at a downstream end; a slot formedinto a top surface of the T-shaped head; a central passage through thevalve body; an annular groove formed into the valve body at approximatea longitudinal center of the orifice body.
 4. The method of claim 1,wherein the step of securing is threading.
 5. The method of claim 1,wherein the step of securing includes receiving a head of the removablehigh pressure orifice body in a cavity in a distal end of the inlettubular union.
 6. The method of claim 1, wherein the step of securingfixes the orifice body within the inlet between the inlet tubular unionand the valve body.
 7. The method of claim 3, further comprising thestep of seating a bottom surface of the T-shaped head upon an outwardfacing surface of the inlet of the valve body and placing top surface ofthe T-shaped head in contact with the inlet tubular union such that theinlet tubular union secures the removable high pressure orifice body inthe inlet.
 8. The method of claim 1, wherein securing the inlet tubularunion to the valve body situates a head of the removable high pressureorifice body inside a cavity formed in a distal end of the inlet tubularunion.
 9. The method of claim 3, further comprising the step ofsituating an O-ring in the annular groove, wherein the O-ring is insealing contact with the walls of the inlet of the valve body.
 10. Themethod of claim 2, further comprising situating an insulating bushing,an insulating ring, and an insulating sleeve within the compensationchamber.